Steam-superheater



D. S. JACOBUS.

STEAM SUPERHEATER.

APPLICATION FILED NOV. 27. 1920,

Patented .Dec. 13, 1921.

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DAVID JACOBUS, OE JERSEY CITY, NEW JERSEY, ASSIGNOR TO THE BABCOCK & 'WIILCOX COMPANY, Oh BAYONNE, N EW JERSEY, A CORPORATION OF NEW JERSEY.

STEAM-SUPERHEATEB.

Specification of Letters Patent. Patented Dec. 13, 1921.

Original application filed August .13, 1915, Serial No. 45,399. Divided and this application filed Novemher 27, 1920. Serial No. 426,758.

To aZZw/iom it may concern:

Be it known that I DAVID S. JAGOBUS, a citizen of the United tates, residing at Jersey City, in the county of Hudson and State of New Jersey, have invented certain new and useful Improvements in Steam-Superheaters, of which the following is a speci-' fication. a

My invention relates to independentlyfired steam superheaters and my present application, which is a division of my prior application Serial No. 45,399 which was? filed in thePatent OfliceAugust 13,1915,

more particularly relates to a superheater having a plurality of chambers and a superheater section in each chamber, the section in the first chamber being so arranged that it is protected from the radiant heat from the combustion chamber.

My invention will best be understood by reference tothe accompanying drawings, in which Figure l is a vertical lon itudinal section through a separately fired superheater embodying-my invention, and Fig. 2 is a horizontal section taken on the plane of the lines 2-2 of Fig. 1.

In thedrawings, the numeral 1 designates a suitable setting made up of brick and structural work and adapted to inclosethe superheater. headers and tubes. At one end of the setting is a furnace Qbeyond which is a vertical wall 3, forming with the front wall, a combustion chamber 4. The space between the wall3 and: therear wallof the setting is divided into a series of chambers by verticalqwalls or baflles 6 and 7 so arrangedas to provide for successive down and up passes for the gases from the combustion chamber to thefiue outlet 39, the walls 6 and 7 being provided withopen ings 24: and 25, respectively, to permit the gases to flow from one chamber to the next. In each chamber is located'a section of the superheater, each section being shown as consisting of lower inlet and outlet headers supportedin the side walls of the setting. The headers are of sufficient diameter to give the desiredvelocity of steam through the superheater, and are shown as flattened at top and bottom. The super-heater tubes the headers and extend upward from the headers to the upper part of the chambers in which the sections are located, with the exception of the first section, the top of which is preferably below the wall 3, as will be more fully hereinafter explained. @pposite each tube end, the header has a handhole which gives access to the ends of the tubesfor expanding and for inspection.

l'have arrangedfin the construction here shown, to first admit the steam to the bank of tubes the most remote from the furnace and to cause it to flow through the superheater in a direction the reverse of the flow of the gases. The steam enters through the valved pipe 32 into the inlet header 33 and, after flowing through the tubes 34, enters the outlet header 35, thence through the connection 36, outside of the setting wall of the superheater, to the inlet header 37 of the middle bank of tubes, and so on to the outlet header 38 of the bank nearest the furnace, and thence to the main steam outlet 39. This arrangement for the flow of the steam is especially'applicable where the bank of tubes which comes nearest the furnace is madeshorter than the others. It will thus be seen that the arrangement of piping which connects the headers of one section of the super-heater to another section is such that the steam enters one header of a given bank of tubes at one side of the superheater and leaves the other header of the same bank atthe opposite side of the superheater, thus leading to a more uniform flow of steam through the superheater tubes than could be obtained should the same enter and leave the headers at the same side of the setting.

The course of the gases is from the secondary combustion chamber at the rear of the furnace, over the wall 3, downwardly over the tubes of the first bank, and then in a general upward and downward direction over the tubes of the middle and rear banks, respectively, to the outlet flue 39.

Dusting doors 40 are provided in the sides of the setting for inserting an air or steam lance for blowing the shot and dust from the interior surfaces of the superheater tubes; part of the dust will be blown away with the gases, and part will settle in, the dust pockets 41 beneath the superheater headers.

While the gases have a general downward and upward fiowthrough the chambers, I prefer to use baflle shelves 27' supported partly upon the headers, and part1 upon abutments projecting from the vertical division walls, to cause the gases to cross and recross the superheater tubes. The headers are preferably placed at. differentlevels, as

shown, the first header being at a higher level in a section where the gases enter at the, top and leave at the bottom, and lower in asection, where the gasesenter at the bottom and leave at the top. By that arrangement, the gases are given a more uniform distribution over the tubes extending upwardly from, the headers.

In: order that all parts of the superheater surface shall be accessible for inspection and for cleaning, I-provide doors 28' in the sides of. thesetting below the level of the headers,

- and doors-29intheside and near the-top of the setting above the superheater loops. I also provide doors 30 opening into. the combustion chamber, which doors may be opened, if: necessary, to permit, cold air to enter; thesuperheater and prevent excessive superheat.

The tubes 31 of the superheater bank, which come nearest the furnace, are made shorter-than thetubes of theother banks so as t'o-bring the top' of thefirst bank below the top of the wall'3. By making the tubes of the-first bank shorter, they are not subj ectedto the direct actionof; the radiant heat fromthe combustion chamber, and it makes possibleto, obtain a greater heat-absorbing capacity from the superheater as awhole, withoutdanger of burning the tubes of, the first bank; or section. Where superheaters areusedto superheat the steam'to the highest, attainable degree, thetubes which: come nearest; the fire eventually burn. out, and haveto be replaced. It isespecially desirablein such a case to make the tubes-of the first bank shorter than those of the other ban-ks,.as in: addition to securing a longer life for the tubes when made shorter, the cost; of: replacing the bank nearest the fire ,when thetubes eventually burn out will be less thanshould it be made up of thelonger tubes. I 7

that I claim and desireto secure by Letters Patent of theUnited States is:

1'. An independently fired superheater comprising a setting, division walls therein to. provide a plurality of. chambers, said walls being-provided with. openings to pernitthe gases to flow through said chambers, a superheater section in each of said chambers, awall-disposed in front of the first section of the superheater and forming with the setting a secondary combustion chamber, the ends of the tubes of the first section of the superheater being short of the opening from the secondary combustion chamber to the first superheater chamber.

2. An independently-fired superheater comprising a setting, division walls therein to provide a plurality .of chambers, said walls being provided with openings, to permit the gases to flow through said chambers, a superheater section in each of said chambers,.a wall disposed in front of the first section of the superheater and forming with the setting a secondary combustion chamber, the ends of the tubes of the first section being below the top of said wall.

An independently-fired superheater comprising a setting, division walls therein to provide a plurality of chambers, said walls being provided with openings to permit the gases to flow'through. said chambers, a superheater section in each of said ehamhers, a wall disposed in front of the first section. of the superheater and forming with the setting a secondary combustion chamber, the, tubes of the first section being shorter than those, of the remaining sections and the tops of the tubes of the first section being located below the top of said wall.

4. An independently-fired superheater comprising a setting, division walls therein to provide a plurality of chambers, said walls being provided with openings to permit the gases to flow through said chambers. a superheater section in each of said cl1a1nhers, a walldisposed in front of the first section of the superheater and forming with the setting a: secondary combustion chamber, the endsof the tubes of the first section of the superheater being located below the top of said wall, the steam entering the rear section of. thesuperheater and flowing forwardly progressively through said sections.

5. An independently-fired superheater comprising a suitable setting, division walls therein to provide a plurality of chambers. a superheater section in each of said chambers, said walls having openings therein to permit a flow of the gases through the chambers, a furnace, a wall at the rear of the furnace to provide a secondary combustion chamber and separating said chamber from the first bank of tubes, the tubes of said first bank being shorter than the height of said last-named wall.

6. An independently -fired superheater comprising a suitable setting, division walls therein to provide a plurality of chambers, a

superheater section in each of said ch amhers.

said walls having openings therein to permit a flow of gases through the chambers successively, a combustion chamber at one end of the setting, and an opening from the combustion chamber into the top of the first superheater chamber, the top of the tubes of comprising a plurality of banks of tubes, the first superheater section being below the and means for directing the heated gases opening in the front Wall, and the tubes of over said banks successively, the tubes in the 10 the remaining superheater sections extendbank over Which the gases first flow being 5 ing substantially to the top of their remade shorter than the others.

spective chambers.

7. An independent1y-fired superheater DAVID S. JACOBUS. 

